R. Kamalesh, A. Saravanan
Rhodamine-B contamination in aquatic environments is a significant environmental concern due to its persistence and potential health impacts. This study evaluates the adsorption performance of raw pomegranate peel waste-loaded ZIF-8 (RPZIF-8) for the removal of Rhodamine-B from aqueous solutions. Material characterization confirmed effective dye uptake, with EDX analysis showing the appearance of a chlorine peak after adsorption, indicating successful Rhodamine-B binding. BET analysis revealed a surface area of 480.7 m2 g−1, while TGA results demonstrated the thermal stability of RPZIF-8 and preservation of the Zn–N framework. Batch adsorption experiments performed at an adsorbent dosage of 80 mg L−1, pH 4, contact time of 50 min, and temperature of 303 K achieved a maximum removal efficiency of 99.18%. The adsorption data were best described by the Langmuir isotherm, indicating monolayer adsorption with a maximum capacity of 782 mg g−1. Thermodynamic analysis confirmed that the process is spontaneous and exothermic, while kinetic studies showed that it follows a pseudo-second-order model. Artificial neural network modeling effectively predicted adsorption performance, yielding an R2 value of approximately 0.99 across training and testing datasets. Regeneration studies demonstrated that RPZIF-8 retained more than 78.45% of its initial adsorption capacity after eight cycles, indicating its potential applicability in wastewater treatment systems.